function CartesianToDegrees(point) {
    var positionCartographic = Cesium.Ellipsoid.WGS84.cartesianToCartographic(point);
    var x = Cesium.Math.toDegrees(positionCartographic.longitude).toFixed(6);
    var y = Cesium.Math.toDegrees(positionCartographic.latitude).toFixed(6);
    return [x,y];
};

function flyInto(ppoint, dur) {
    var camera = scene.camera;
    camera.flyTo({
        destination: Cesium.Cartesian3.fromDegrees(ppoint[0], ppoint[1], ppoint[2]),
        duration: dur
        // orientation : {
        //     heading : Cesium.Math.toRadians(70.0),
        //     pitch : Cesium.Math.toRadians(-15.0),
        //     roll : 0.0
        // }
    });
};


// 根据经纬度获取高度
function getHeigthByLonLat(lon,lat){
    var positions = Cesium.Cartographic.fromDegrees(lon,lat);
    var promise = new Cesium.sampleTerrain(viewer.terrainProvider, 13, [positions]);
    promise = Cesium.sampleTerrainMostDetailed(viewer.terrainProvider, positions);
    Cesium.when(new Cesium.sampleTerrain(viewer.terrainProvider, 13, [positions]), function (updatedPositions) {
        console.log("zhang",lon,lat,updatedPositions[0].height);
    });
}
